Safety device for elevators.



E. A. HANFF.

SAFETY DEVICE FOR ELEVATORS.

APPLICATION men JULY 30.19M-

1,215,524. Patented Feb. 13, 1917.

2% f c 5 Pk a E y E LP 11 noon H 4 WlTNESSES: INVENTOR gzafl [fl'Wd/d A.Ham? BY ATTORNEY OF WILKINSBURG, PENNSYLVANIA, ASSIGN OR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SAFETY DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Patented Feb. 13, 1917.

Application filed July 30, 1914. Serial No. 854,017.

To all whom it may concern:

Be it known that I, EDWARD A. HANFF, a citizen of the United States, anda resident of \Vilkinsburg, in the county of Allegheny and State ofIennsylvania, have invented a new and useful Improvement in SafetyDevices for Elevators, of which the following is a specification.

My invention relates to safety devices for elevators and it has for itsobject to provide a simple. means for preventing injury to persons whosebodies may be interposed between the car and the elevator shaft.

In the operation of elevators, it sometimes occurs that persons, eitherthrough accident or inadvertence, are caught between the moving car andthe casing of the door or opening in the elevator shaft. In such cases,it is practically impossible for the operator to stop the car in time toprevent serious injury to the person placed in such a position.

According to the present invention, I provide a buffer which may belocated either upon a car or upon the walls of the elevator shaft, orboth, and which operates, upon its engagement with an object between itand the car or the shaft, as the case may be, to open the circuit of themotor and bring the car to rest. While my invention is intendedprimarily to prevent injury may operate equally as well to preventdamage to the elevator mechanism, in case some object be interposedbetween the car and the elevator shaft.

In the accompanying drawings, Figure 1 is a view, partially in elevationand partially in section, of a portion of an elevator system with myinvention attached thereto. Fig. 2 is a similar view of the mechanism ofFig. 1, taken at right angles thereto. Fig. 3 is a view, in elevation ofa modification, parts being broken away. Fig. 4c is a diagrammatic viewof circuits and apparatus embodying my invention Referring particularlyto Figs. 1 and 2, an elevator car 1, which is adapted to operate in ashaft having side walls 2,'is provided with the usually manuallyoperable controller 3. The elevator shaft is provided, at each floor,with the usual door or opening 4: and a sliding gate A safety device 6comprises a buffer 6 having a rod 7 which is slidably mounted insupports 8 that are attached to the walls 2 above the opening 4.Normally, the bufl'er to persons, it

6 is retained in the position shown by a spring 9. The upper end "of therod 7 is adapted to engage a roller 10 which is mounted at one end of alever 11. The opposite end of the lever 11 carries a contact member 12which coacts with a stationary contact member 13. The contact members 12and 13 are arranged in a manner to be later described, to control thecircuit of the motor which operates the elevator.

A similar safety device 20 is attached to the floor of the car 1 andprojects downwardly therefrom. The second safety device difl'ers fromthat described above only in that it comprises two springs 9 whichoperate to maintain it in the position illustrated.

A modification is illustrated in Fig. 3 in which similar numerals areemployed to designate corresponding parts. The buffer 6 and the coactingcontact members 12 and 13 controlled by it are mounted upon the top ofthe elevator car 1 instead of being mounted upon the stationary wall 2and 'above the door 4, as in Figs. 1 and 2. This form of my inventiondifiersmaterially in no other respect from the structure described inconnection with Figs. 1 and 2.

The circuits and apparatus embodying my invention are diagrammaticallyillustrated in Fig. 4. Line conductors 14 and 15, which may be connectedto any suitable source of current, supply energy to an electric motor16. The motor circuit is controlled by a two-pole electromagnetic switch17 comprising an actuating coil 18. The circuit of the coil 18, which isnormally controlled by the controller 3, comprises also the contactmembers 12 and 13 of the safety devices.

It will be readily understood that, if, during the operation of the car,the body of a person or other object is interposed between either thetop or the bottom of the car and the walls of the elevator shaft, thecorresponding buifer 6 will be actuated to separate the contact members12 and 13 and thereby open the circuit of the coil 18. The switch 17opens the circuit of the motor 16,. and the car is immediately broughtto rest by the usual automatic brake (not shown). IVhen either of thesafety devices has been actuated, the controller 3 is inoperative tocomplete the circuit of the motor until the corresponding buffer 6 hasbeen released to complete the controller circuit at the contact members12 and 13. The force required to separate the contact members 12 and 13may be predetermined by a proper selection of the spring 9. It may bedesirable, under some circumstances, to provide means for actuating thecar in the reverse direction to release the person or object after thecar has stopped.

While I have shown and described my invention as applied to an elevatorsystem employing electric motors, it may be adapted, by obvious changes,for use in connection with elevator systems employing other forms ofmotive power.

The advantages of my invention are that it is simple in construction andautomatic in its operation to bring the car to rest quickly when anyobject is interposed between the car and the walls of the elevator shaftand thus prevent injury to persons entering or leaving the car anddamage to the elevator mechanism.

I claim as my invention:

1. In an elevator system, the combination with a car, a structure forinclosing said car, a motor for actuating said car and a controller forsaid motor, of means for rendering said controller and said motorinoperative when an object is interposed between said car and saidinclosing structure, said means comprising an electromagnetic switch forcontrolling the motor circuit having an actuating coil in series withsaid controller and a yielding member for controlling the circuit ofsaid coil.

2. In an elevator system, the combination with a car, a structure forinclosing said car, a motor for actuating said car and a controller forsaid motor, of means for rendering said controller and said motorinoperative when an object is interposed between said car and saidinclosing structure, said means comprising an electromagnetic switch forcontrolling the motor circuit having an actuating coil in series withsaid controller, a switch forcontrolling the circuit of said coil andsaid controller and a yielding member for controlling said switch.

3. In an elevator system, the combination with a car, a structure forinclosing said car, a motor for actuating said car and a controller forsaid motor, of means for rendering said controller and said motorinoperative when an object is interposed be tween said car and saidinclosing structure, said means comprising an electromagnetic switch forcontrolling the motor circuit having an actuating coil that is normallyenergized when the controller occupies an operative position andayielding member for efiecting the opening of the circuit of said coilunder predetermined conditions.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof July, 1914.

EDIVARD A. HAN F F.

\Vitnesses:

W. B. BASSETT, B. B. HINES.

